Does pouring water on it count as an external stimulus?
Wind?
Resolved: Fire is alive
If you count oxygen supply as an external stimulus, fire is irritable. Denied oxygen, it can become sleepy and dormant. Offered more than 21% oxygen (as a component of atmospheric air), it becomes quite excited. Feeding it different fuels also has a marked effect on how a fire behaves.
I don’t think so. After all, if you shoot somebody in the head, they fall over dead - but this isn’t stimulus-response as most people would understand it.
Wind is a better counterexample. Maybe the definition I was taught in school won’t do. It wouldn’t be the first time my formal education has failed me.
Although fires can be said to reproduce, their reproduction is different from that of living organisms in a crucial way: Living organisms produce offspring which resemble their parent or parents more than they do other members of that same type of organism. This is not the case with fires; they extert no “control” over what characteristics their “offspring” take, which instead is completely dependent on the environment. A spark from a pile of burning magnesium shavings may land in a pile of wood chips and ignite them, but the “daughter” fire won’t be a magnesium fire any more–you would be able to put out the daughter fire of burning wood chips by pouring water on it, for example (which would be a bad idea with the “mother” magnesium fire). A spark from the wood fire may in turn ignite a pool of oil, or set off a coal seam; in each case, the new fire will resemble other oil fires or coal fires, and not the parent or grandparent fires. Fire therefore never evolves in a Darwinian way; and I suspect “undergoes evolution by natural selection” may be fundamental to the definition of life.
Paging Una Persson.
Regarding “Is fire alive,” my question is this: What’s the point of distinguishing between living and non-living things?
Right; it seems to me that, as far as the life we’ve seen on this planet goes anyway, the crucial distinction is between stuff we’re genetically related to and everything else.
Looked at that way, though, you’re still ruling out eunuchs and old women. A better interpretation of the “reproduction” criterion is that a living thing (even a priest, eunuch, or grandmother) is made up of parts which reproduce.
Is it true that iron that is rusting is really undergoing a verrry slow fire?
Only in a verrry loose definition of fire. Rusting is oxidation, but the most common definition of fire includes properties not present in rusting, such as gaseous plasma.
Interesting discussion.
Going back to the OP, what if I was looking for a flame instead of smoldering coal? What is the longest lasting flame in history?
Close your eyes and give me your hand
Do you feel my heart beating, do you understand?
Do you feel the same, am I only dreaming
Or is this burning an eternal flame?
Quoth the Bangles…
The old flame, the burning in my loins this heartlamp that I’ve been carrying, baby. That’s one anthropomorphization of fire.
Sacred Heart aflame…
Perhaps fire was intelligently designed?
d&r
Another link to an earlier thread somewhat related to this subject, with some interesting discussion as to the definition(s) of life.
From NFPA 921: Guide for Fire and Explosion Investigations
I wouldn’t call it a loose definition, but instead an equivalent reaction at a greatly reduced rate of propagation. 
We the shepards of fire, to shield, propagate, and direct.
Its essence, harness of direction and mind.
Eternal at our will.
Long as we, Longer than we.
Destruction and life…rebirth and infinite.
I am a servant of the Secret Fire, wielder of the Flame of Anor: dark fire will not avail you, Flame of Udun!
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